1 <?xml version="1.0" encoding="utf-8"?>

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     7     Nokia Corporation - initial contribution.

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    10 <!DOCTYPE concept

    11   PUBLIC "-//OASIS//DTD DITA Concept//EN" "concept.dtd">

    12 <concept id="GUID-6690CEFF-AE08-4881-AF52-70C097EB2871" xml:lang="en"><title>Unavailable

    13 items</title><prolog><metadata><keywords/></metadata></prolog><conbody>

    14 <p>Situations often occur where a certain function cannot be used. In these

    15 cases, the corresponding items in the Options menu must either be hidden,

    16 or there must be an error message given when the user tries to access a function

    17 that cannot be accomplished. The Symbian user interface does

    18 not use dimming of menu items.</p>

    19 <p>This is a trade-off issue: removing unnecessary options makes the Options

    20 menus shorter, but at the same time it changes the menu from situation to

    21 situation, preventing users from learning the function locations. It may even

    22 cause frustration if the users expect some function to be found in the menu,

    23 but it is sometimes not there.</p>

    24 <ul>

    25 <li><p>In case the user has no reason to search for a certain function in

    26 the given situation, it should be hidden. As an extreme example, the Delete

    27 option is not needed when there are no items to be deleted. </p></li>

    28 <li><p>If the user searches for a function, even though it cannot be used

    29 in the current situation, it is often better to display the option and give

    30 an appropriate message if the user tries to access that function.</p><p><ul>

    31 <li><p>An example of this is Digital Rights Management (DRM) protected files:

    32 for example, sending commands shall be visible in the user interface although

    33 sending such a file would not be allowed. Appropriate DRM-specific notifications

    34 are displayed if the user attempts to select one of the options that the user

    35 is not allowed to perform on DRM-protected media objects. This is to facilitate

    36 end-user's learning of the DRM concept.</p></li>

    37 </ul></p></li>

    38 </ul>

    39 </conbody></concept>